Engine control means



Aug. 4, 1942. F. BLYMYER ENGINE CONTROL MEANS 3 Shets-Sheec- 1 Filed May 29, 1941 3nnentdr Fiazzkfizymyeb (Ittornegs F. BLYMYE R ENGINE CONTROL VMEANS Aug.'4, 1942.

Filed May 29 1941 3 Sheets-Sheet -2 3nnentor fazzk Big hiya A118. 4, 1942. F. BLVYMYER 2,292,394

ENGINE ,GONTROL MEANS Filed May 29, 19 4; 3 Sheets-Sheet 3 Inventor 752222]; Blyfzgyeb attorneys Patented Aug. .4, 1942 UNITED STATES PATENT OFFICE ENGINE CONTROL MEANS Frank Blymyer, Westchester, Ill., assignor to General Motors Corporation,

poration of Delaware Application May 29, 1941, Serial No. 395,848

Claims.

This invention relates to control means for an engine.

It relates especially to a combined manual and governor control means for an internal combustion engine working under varying conditions of load and speed.

The object of the invention is a combined manual and governor actuated control means; such that the governor is only operative in the low and high speed ranges, to control the engine when idling and to prevent a maximum speed from being exceeded; the engine being controlled in an intermediate speed range by the manual means alone.

A more specific object of the invention is a combined manual and hydraulic governor con trol means of the foregoing kind.

The above and other objects of the invention will be apparent as the description proceeds.

According to the invention, the manual control means and the fuel control member are connected to spaced points of a floating lever having a third point connected to a second floating lever, at a point removed from two spaced points thereof which are respectively positioned by two independent servo motor means controlled by the governor in its high and low speed ranges respectively. When one of the servo motor means is operative, the other is stationary in a fixed position and vice versa, the first floating lever being moved differentially by the manual control means and one or the other of the servo motor means. In the intermediate speed range both servo motor means are inoperative and stationary in fixed positions, providing a fixed fulcrum for i the first floating lever which is oscillated thereabout by the manual control means to move the fuel control member.

The drawings show an embodiment of the invention in which the governor is of the hydraulic relay type.

In the drawings Figure 1 is a view of the associated parts of the control means in sectional elevation. v Figure 2 is a view on line 2--2 of Figure 1.

Figure 3 is a view on line 3--3 of Figure 1 with part broken away.

Figure 4 is a view of a detail on line 4-4 of Figure 1. I

As shown most clearly in Figure 1, the housing I contains a hollow shaft 2 driven by the engine,

and provided with a governor head 3 on which flyweights 4 are pivotally mounted.

The flyweights 4 control the position of a pilot valve 1. With increasing engine speed the fly- 55 Detroit, Mich, a corweights move outwards about their pivots, liftvided with three spaced annular grooves l2, I3,

and I4, separated by lands i6 and l1, and it controls ports 20, 2|, 22, 23, and 24 through the wall of the hollow shaft 2. The said ports open into annular grooves in the exterior circumference of the revolving shaft .2, through which communication is at all times maintained with ports and ducts in the housing I, hereinafter described.

Secured to the lower end of the shaft 2 is a gear wheel 26 of agear wheel pump which delivers lubricating oil under pressure to a chamber 28 from a chamber 29 connected with the engine lubricating system by a pipe 30.

From the chamber 28 there are ports 32 and 33 communicating at all times with the ports 20 and 23 respectively of the hollow shaft 2, and a spring loaded pressure relief valve 35 puts the chamber 28 in communication with a return line 36 to the inlet side of the pump. Oil flowing through the ports 32 and 20 into the annular groove l2 of the pilot valve, can pass therefrom through the .port 2| and ducts (not shown) to a cylinder 40 (Figure 2) containing a. servo piston 4i; but at the highest engine speeds, as the pilot valve I is lifted, the annular groove l3 puts the port 2| and hence the cylinder 40 in communication with the drain port 22 which returns the lubricating oil to the engine lubricating, system through a suitable duct (not shown).

Oil flowing through the ports 33,and 23 into the annular groove I4 of the pilot valve can pass therefrom through the port 24 and ducts (not shown) to a cylinder 44 (Figure servo piston 45; but in th idling speed range and above, as the pilot valve 1 is lifted, its lower end first closes the port 24 and then opens it to the hollow shaft 2 through which the lubricating oil is drained from the cylinder 44, back to the engine lubricating system.

As most clearly "shown in Figures 2 and 3, a bushing 48 in the housing I, supports a short shaft 49, to the outer end of which is secured a lever arm 50 constituting a fuel control member by which fuel control mechanism (not shown) is actuated.

2) containing a Secured to the inner end of the shaft 49 is a lever arm 52, the end of which carries a link pin 53 which engages a slot in one end of a floating lever 54. The other end of the floating lever 54 may be moved by a manually actuated lever 59 secured to the outer end of a short shaft 6|! in a bushing 6| in the housing i, said shaft having between the pivot pin 65 of the floating lever 54 and a pivot pin 68 intermediate the ends of a second floating lever 69, to the opposite ends of which the servo pistons 4| and 45, are respectively connected by pivot pins H and T12, which engage slotted holes 14 and 115, in the lever 69.

Upward movement of the rod M is resiliently resisted by a coil spring ll.

Movement of the rod 51 isarranged to vary the governor spring loading by movement of the abutment iii of the springs 9 and 9 which is effected by means of a yoke l8 fulcrumed to the fixed guide it by pivot pins l9, and linked to the rod 6? by the pivot pin 89. As the rod (S'l is lowered to reduce the amount of fuel supplied to the engine, the governor spring loading isincreased and vice versa, thus tending to stabilize the pilot valve and the movements of the servo pistons controlled thereby.

A spring latch 8| holds the rod 67 and its linkages in starting position, in which the yoke 78 and the abutment In which is connected thereto by coil springs 82 in tension, are lifted to relieve the governor of the load of the springs B and 9 and the weight of the abutment Ill and associated parts whenever the engine is not running. The latch 8| is released by the pressure of the oil in chamber 28 which flows through the ports 32 and 20, the annular space l2 of the pilot valve l, and a port 83, and thrusts against a plunger 84 whenever the engine is running. The plunger 84 has a stem 85 extending through a slot 86 in the rod 61 and releases the latch 8| by direct thrust against the end thereof.

The pilot valve 1 is provided with an extension 81 constituting a shut down rod through which it can be positively lifted by a lever 88 pivotally mounted on a pin 89 in the housing, and having an arm 90 which rests on the pin 64. Downward fuel closing of? movement of the manual control means 59 raises the pivot pin 64, the two lever arms 88' and 90, and the pilot valve 7, to a position in which the relief port 24 of the pilot valve is open, the servo piston- 45 is at the bottom of its cylinder, and no fuel is supplied to the engine. The shape of the slot 65 in the floating lever 54 is such as to permit of the aforesaid movement of the manual control means 59 to shut down position at any time with lost motion between the lever 63 and the floating lever 54 when the rod 61 is in the latched position.

The drawings show the position of the parts with the engine stopped, the rod 51 latched, the manual control lever 59 raised to a position in which the pin 64 is towards the bottom of the slot 65 in lever 54, with the pilot valve lowered from its shut down position to the starting position shown in Figure l; 9. lug 92 on the lever 52 being against a stop 93, with the lever arm 50 constituting the fuel control member in a position in which no fuel is supplied to the engine. It'will be seen, however, that any further upfriction damper.

ward movement of the manual control lever 59 or of the rod 61, or both, will move the lever 52 away from its stop 93, and the lever 50 to a position permitting the supply of fuel to the engine, and hence the starting of the engine. As the engine is cranked and gains speed, the oil pressure in the chamber- 28 rises, releasing the latch 8|, and oil flows through the port 2| to the cylinder 49 to maintain the servo piston 4| against a stop 94 in the position shown in Figure 2. At the same time the oil flows through the port 24 to the cylinder 44, raising the servo piston 45 to a maximum extent/limited by the stop 95, and thereby lifting the rod 6i and with vrards and the lever arm 59 downwards to increase the fuel supply.

If the engine speed rises higher than the idling speed of say 450 to 700 R. P. M., the pilot valve l is raised by the governor weights 4, and opens the relief port 24 so that the fluid pressure in the cylinder 44 is relieved, and the servo piston 45 descends with the rod fill, which reduces the amount of fuel supplied to the engine.

Movement of the servo piston 45 under the control of the pilot valve 1 will keep the engine running in its idling speed range despite small fluctuations in load.

When, however, the manual control lever 59 is raised to supply sufficient fuel to the engine to maintain it in an intermediate speed range, the pilot valve I is lifted by the governor weights 4, its lower end completely uncovers the relief port 24, the cylinder 44 is drained, and the servo piston 45 returns to the position shown in Figure 2.

Both the servo pistons 4| and 45 remain in the position illustrated in Figure 2 throughout the intermediate speed range in which the automatic Should the engine speed rise higher than, say

1750 to 1800 R. P-. the pilot valve l is lifted by the governor weights 4 to a position in which the annular groove I3 puts the port 2|, and hence the cylinder 40, in communication with the drain port 22, so that the servo piston 45 moves downward with the rod 61, which reduces the amount of fuel supplied to the engine.

Movement of the pilot valve 1 is damped by a As shown most clearly in Figure 4, this consists of a cylindrical slug 91, backed by a spring 98 in a pocket 99 in the housing and bearing against the side of the extension rod 81 of the pilot valve. The pressure of the spring 98 and hence the degree of friction damping is variable by adjustment of a screw I90.

I claim:

1. Combined manual and governor control means for an internal combustion engine including a manual control means, a fuel control mem her, and a governor, said manual control means and said fuel control member being respectively connected to spaced points of a floating lever of which a third point spaced from the first mentloned spaced points is connected to a second floating lever at a point removed from two spaced points thereof which are respectively positioned by means responsive to the governor in its high and low speed ranges respectively,

2. The combination according to claim 1, in ,which the means responsive to the governor are two independent servo motor means. v

3. The combination according to claim 1 in which the connection between the floating levers is a rod with spring means resiliently urging the rod, the floating levers and the fuel control member in a direction to reduce the fuel supply.

4. The combination according to claim 1 in which the connection between the floating levers is a rod with spring means resiliently urging the rod, the floating levers and the fuel control members in a direction to reduce the fuel supply,

there being means connected with the rod for increasing the governor spring loading upon movement of the rod in said direction.

5. In an engine fuel control, the combination of an engine driven centrifugal governor, an en-- gine driven source of fluid under pressure, a pair of cylinders containing pistons movable by the pressure fluid and operatively connected with a fuel control member, and pilot valve means controlled by the governor to supply pressure fluid to said cylinders, to cut oil! the supply thereto, and to control the eiiiux from one of said cylinders in the low speed range of the governor and from the other cylinder in the high speed range of the governor.

- FRANK BLYMYER. 

